A 3D porous interconnected NaVPO₄F/C network: preparation and performance for Na-ion batteries

Abstract

3D porous interconnected NaVPO4F/C network is fabricated by a hydrothermal method and sintering process. As a Na-ion battery cathode material, it delivers a good electrochemical performance.

Challenges and Perspectives for NASICON‐Type Electrode Materials for Advanced Sodium‐Ion Batteries

“…Besides NVP and NVPF, there are many other interesting materials following the general NASICON formula Na x MM'(XO 4 ) 3 (M = V, Ti, Fe, Tr or Nb; X = P, or S, x = 0–4), such as NaVPO 4 F, Fe 2 (MoO 4 ) 3 , Na 1.5 VOPO 4 F 0.5 , Na 3 (VO 1–x PO 4 ) 2 F 1+2x (0 ≤ x ≤ 1), Na 2 TiFe(PO 4 ) 3 , Na 3 Fe 2 (PO 4 ) 3 , and NaNbFe(PO 4 ) 3 etc . For instance, Na 3 (VO 1–x PO 4 ) 2 F 1+2x (0 ≤ x ≤ 1) composites were prepared via a novel solvothermal low‐temperature (60–120 °C) method, delivering high capacities (110 mAh g −1 when x = 1; 112 mAh g −1 when x = 0) and good cycling performances (high capacity retentions of 93.6% and 93.8% after 200 cycles at 0.2 C, respectively) .…”

Vanadium‐Based Nanomaterials: A Promising Family for Emerging Metal‐Ion Batteries

“…But the capacity was found to decrease to less than 50% only after 30 cycles. To improve the electrochemical performance, several strategies such as Cr doping, carbon coating and graphene modification have been reported. The graphene modified NVPF reported by Ruan et al exhibits distinct increased capacity of 120.9 mAh g −1 at 0.02 C with capacity retention of 97.7% after 50 cycles.…”

Electrospun NaVPO4F/C Nanofibers as Self‐Standing Cathode Material for Ultralong Cycle Life Na‐Ion Batteries

“…The root problem is traditional technology for preparing NaVPO 4 F mainly based on the high-temperature solid-state reaction, sol-gel method, and hydrothermal method, which often produce bulk or micrometer-sized NaVPO 4 F particles with insufficient carbon coating, leading to rapid capacity fading since this structure is unfavorable to electron transfer and the permeation of electrolyte. [31,32,34] Hence, it is significant to enhance the kinetics of Na-ion transfer in NaVPO 4 F. In order to achieve this goal, strategies mainly include decreasing the crystallite size and altering morphology of the material. [7,22,35,36] As far as we know, electrospinning is a versatile technique to prepare various 1D carbon-containing composites and produce flexible membrane, [6,8,[37][38][39] which encourages us to fabricate NaVPO 4 F with novel morphology combined the method of electrospinning to improve its electrochemical performance.…”